3 Best Sights in Salamanca, Castile–Leon and Castile–La Mancha

Founded in 1419, this convent hides a 16th-century cloister that is the most fantastically decorated in Salamanca, if not all of Spain. The capitals of its two superimposed Salmantine arcades are crowded with a baffling profusion of grotesques that can absorb you for hours. Don't forget to look down: the interlocking diamond pattern on the ground floor of the cloister is decorated with the knobby vertebrae of goats and sheep. It's an eerie yet perfect accompaniment to all the grinning disfigured heads sprouting from the capitals looming above you. The museum has a fascinating exhibit on Spain's little-known slavery industry.  Seek out the traditional sweets made by the nuns.

The convent's monks, among the most enlightened teachers at the university in medieval times, introduced Christopher Columbus to Isabel (hence his statue in the nearby Plaza de Colón, back toward Calle de San Pablo). The complex was designed by one of the monks who lived here, Juan de Álava. The west facade, a thrilling plateresque masterwork in which sculpted figures and ornamentation are piled up to a height of more than 98 feet, is a gathering spot for tired tourists and picnicking locals, but the crown jewel of the structure is a glowing golden sandstone cloister with Gothic arcading punctuated by tall spindly columns adorned with classical motifs. The church, unified and uncluttered but also dark and severe, allows the one note of color provided by the ornate and gilded high altar of 1692. An awe-inspiring baroque masterpiece by José Churriguera, it deserves five minutes of just sitting and staring.

Nearest the river stands the Catedral Vieja (Old Cathedral), built in the late 12th century and one of the most riveting examples of the Spanish Romanesque. Because the dome of the crossing tower has strange plumelike ribbing, it's known as the Torre del Gallo (Rooster's Tower). The much larger Catedral Nueva (New Cathedral) went up between 1513 and 1526 under the late-Gothic architect Juan Gil de Hontañón. Controversially, a 1992 restoration added an astronaut carving to the facade as a wink to the modern era—see if you can spot it. Both cathedrals are part of the same complex; enter the new to get to the old.